Electromagnetic mechanism



Aug. 24, 1948. v, ALVINO ELECTROMAGNETIC MECHANISM Filed Dec. 3, 1942 O 9: m a V "W a; M? 2 TA N m .m O O a m R T S O 7 6 a N T 5 Z O T P 9 w a 0 L M 7 a A% i W 5 7 7 I 7 3 Z a 97 A Y. z B m a 2 m 0 71+;

Patented Aug. 24, 1948 UNITED STATES PATENT osncs ELECTROMAGNETIC MECH.ANISM Alphonse V. Alvino, Newark, N. J., assignor to Bendix Aviation Corporation, Bendix, N. J., a corporation of Delaware Application December 3, 1942, Serial No. 467,777

6 Claims. (Cl. 200-111) This invention relates to electromagnetic mechanism, and more particularly to electromagnetic mechanism of the solenoid type, in which the magnetic circuit includes a closeable gap located within a current receiving winding, or coil.

In the accompanying drawing the invention is shown in an embodiment which has been favorably received for use as part of a system of control of the energization of high amperage circuits of the type employed in aircraft electrical systems; but of course the accompanying drawing is illustrative only, and is not intended as a definition of the limits of the invention, refer ence being had to the appended claims for this purpose.

To a certain extent the illustrated embodiment follows the pattern of the solenoid switch mechanism disclosed in Patent No. 1,803,908 granted to Raymond P. Lansing on May 5, 1931. The departures from the Lansing disclosure will be described in detail, as they embody the novel features of the present invention.

It is an object of the present invention to provide a solenoid switch which is positive in action, but which operates with small current consumption.

It is another object of the invention to provide such a device which embodies a release spring amply strong to insure a positive, quick break under all circumstances.

Another ob ect is to provide a device of the above character which is desi ned to have a hi hly efficient magnetic circuit. causin firm effective contact without undue current consumption.

A further object is the provision of such a device which is comparativel small and light so as to provide a quick, clean break of the contacts.

Another object'is to provide a novel terminal assembly, featuring a single terminal cup to securely hold both switch and coil terminals.

Another object is the provision of a magnetic switch which is inexpensive to manufacture, and in which the parts may be readily assembled or removed for inspection or replacement.

Other objects and advantages will be apparent from the following description taken in connection with the disclosure in the accompanying drawing.

In the drawing:

Fig. 1 is an end view of a device embodying the invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on line 33 of Fig. 2;

Fig. 4 is an end view; and

Fig. 5 is a view of the terminal cup.

Referring first to Fig. 2 of the drawing, numeral I0 indicates a cup-shaped shell or casing member, preferably formed as a steel stamping. The member I0 is closed at its open end by a bracket H which extends laterally therefrom and is provided with a flange 12 by which the switch ..may be mounted in any desired location, such as a motor or upon any other part to be associated therewith. Screws 9 hold cup [0 to bracket II.

The cup I0. is placed back-to-back with respect to a second cup l3 of insulating material, and the two are held together by suitable means such as screws I having their heads seated in the base of cup l0 and their threaded ends clamped to cover I6 (see Fig. 3) to hold the parts in assembled relation. Cup I3 is provided with a rectangular ledge portion I3A, also laterally projecting portions l5 having openings in which terminal members I! and 18 are mounted. These terminal members are in the form of threaded bolts of good conducting material. such as copper or brass. and receive bars I9 and 20 which pass through slots 5| in cup I3 and act as the stationary contacts of the switch. Suitable nuts 2|, 22, are threaded onto the outer portions of the bolts for securing the same to the terminal cup I3. and for attaching the conductors (not shown) to said bolts. The heads of the bolts I! and [8 have their sides in re i try with the straight sides of ledge I3A (see 1) and thus are locked against any turning tendency which might otherwise loosen the circuit connections. The same is true of heads 42 of terminal bolts M. to which the coils ends 43 connect. These ends 43 pass through small o enings 44 in cup Ill, to connect with terminals 42.

The closure plate II is provided with a central opening, and a pole-piece 25 is mounted with its outer end suitably fixed in said opening, as by means of the lip 26 expanded therein. A plunger 30 of magnetic material, having a slightly smaller diameter than the outside diameter of guide member 36, has suitably fixed thereto a rod 3| and serves as a movable pole-piece to cooperate with the fixed pole-piece 25. Rod 3| carries contact assembly 21, also a disc 32 which retains a coiled spring 29 under compression, thus assuring steady engaging pressure on contact assembly 21 when the coil 34 is energized.

A spool or core 33 of suitable insulating mateshaped shell of non-conducting material. means for securing said cup-shaped shells in back-toback abutment, said second-named shell having straight-edged exterior plane surfaces on several sides thereof. a pair of terminal screws having heads engageable with one of said plane surfaces.

' means for attaching the coil ends to said terminal when the control circuitthrough the solenoid winding 84 is closed by the operator in any suitable manner (as by means of a remote control switch) the magnetic flux produced in said winding 34 will move the plunger 30 to the right, compressing the spring 31 and moving the plateof the contact assembly 21 into intimate engagement with the terminal bars l9 and 20 of the controlled circuit. This closes said circuit and-causes the operation of the motor or other part to be energied. when the control switch is opened by the operator, the magnetic flux of the solenoid drops almost instantly to zero, and spring 31 instantly and forcibly thrusts the contact assembly 21 away from the terminal bars I 9 and 20 in spite of any burning together of the surfaces thereof which may have taken place, and so rapidly that any appreciable amount of arcing is prevented.

In order to permit the coil to elongate in one direction in response to absorption of heat, there is provided a flat spring 55 having a normally bowed disposition, as shown in Figs. 2 and 3, and operatively engaging a disc 56 abutting the coil spool 33, the spring being flexed so as to normally bear against the surface of disc 56. The spring thus constitutes a resilient support for the coil and permits an elongation of the coil in response to absorption of heat therein; expansion in the other direction being prevented by the engagement with the flange provided on sleeve 33 ad.'acent bracket il.

Thus it is apparent that the expansion of the coil cannot interfere with the calibration of the switch, since such expansion does not cause any variation in the width of air gap between the fixed and movable pole-pieces 25 and 30, respectively.

Sleeves 51, of insulating material, have flat external surfaces which, like flat-sided bolt-heads l1, l8 and 42, serve to resist any turning tendency of screws i4.

.What is claimed is:

1. In a magnetic switch, a pair of cup-shaped members, one of the cup-shaped members being formed of an insulating material and the other of said members being formed of a magnetic material, means for holding said cup-shaped members in back-to-back abutment, said means including screws extending through said one cupshaped member, a current receiving coil in the other of said cup-shaped members, and a switch element operated by said coil, the terminals for both said coil and said switch element being carried by said one cup-shaped member and cooperating therewith in such manner as to resist loosening of the terminal connections.

2. In a solenoid switch, a cup-shaped shell of magnetic material, a solenoid coil therein, a cupshaped shell of non-conducting material, said latter shell having straight-edged plane surfaces on several sides thereof, a pair of terminal screws carried by the second-named shell and having heads engageable with one of said plane surfaces, and means for attaching the coil ends to said terminal screws, said coil ends being led through spaced-apart apertures in said first-named shell.

3. Ina solenoid switch, a cup-shaped shell of magnetic material, a solenoid coil therein, a cupscrews, said coilv ends being led through spacedapart apertures in said first-namedshell, and means housed in said second-named shellfor closing a circuit in responseto flow of current through I said coil, said last-named means including a circult bridging element, a pair of conducting bars engageable by said bridging element, and terminal screws passing through said bars for securing said bars to said second-named shell, each of said terminal screws having a head engageable with one of the straight-edged exterior plane surfaces of said second-named shell.

4. In a solenoid switch, a cup-shaped shell of magnetic material, a solenoid coil therein, a cupshaped shell of non-conducting material, means for securing said cup-shaped shells in back-to- .back abutment, said second-named shell having straight-edged exterior plane surfaces on several sides thereof, a pair of terminal screws having heads engageable with one of said plane surfaces, means for attaching the coil ends to said terminal screws, said coil ends being led through spaced-apart apertures in said first-named shell, and means housed in said second-named shell for closing a circuit in response to how of current through said coil, said last-named means including a circuit bridging element, a pair of conducting bars engageable by said bridging element, and terminal screws passing through said bars for fastening said bars to said second-named shell at the exterior thereof, each of said terminal screws having a head engageable with one of the straight-edged exterior plane surfaces of said second-named shell, said second-named shell having slotted openings at diametrically opposed areas through which said bars project to the exterior.

5. In a solenoid switch, a cup-shaped shell of magnetic material, a solenoid coil therein, a'cupshaped shell of non-conducting material, said second named shell having straight-edged plane surfaces on several sides thereof, and means housed in said second-named shell for closing a circuit in response to flow of current through said coil, said means including a circuit bridging element, a pair of conducting bars engageable by said bridging element, and terminal screws having heads engageable with one of the straight-edged plane surfaces, said terminal screws passing through said bars and securing said bars to said second-named shell.

6. In a solenoid switch mechanism, a cupshaped shell of magnetic material, a solenoid coil therein, a. cup-shaped shell of non-conducting material, switch means housed in said secondnamed shell for closing a circuit in response to flow of current through said coil, means for holding said cup-shaped'shells in back to back abutment, said second-named shell having an exterior edged surface, terminal screws for the solenoid switch mechanism, said terminal screws carried by said second-named shell, electrical connections for said solenoid switch mechanism leading to said terminal screws from the interior of at least one of said cup-shaped shells, said terminal screws having heads engageable with said exterior edged surface of the second-named shell and cooperating therewith in such a manner as to 112- Number sist loosening of the terminal connections. 590,420

ALI-HORSE V. ALVINO. 732 351 REFERENCES CITED 5 The following references are of record in the 1,803,908 file of this patent: UNITED STATES PATENTS 1,989,052 Number Name Date 2,324,301

571,977 Manger Nov. 24, 1898 6 Name Date Lundeil Sept. 21, 1897 Hanchett July '7, 1903 Halbleib et a1 Aug. 28, 1917 Day June 24, 1930 Lansing May 5, 1931 Leece Aug. 4, 1931 Plachy Feb. 23, 1932 Gillen Jan. 22, 1935 Heintz July 13, 1943 

